“I can hear you…but I can ‘t understand you…” This statement best exemplified one of the most common reasons for middle-aged and older adults to consult an audiologist. While problems in understanding speech, especially in noisy environments, become more prevalent with age, the cause(s) are not always so easy to determine. Researchers at Baycrest are using a new approach in studying the impact of age and noise on how the brain codes, transforms, and ultimately renders auditory percepts. The study aims to determine whether speech in noise problems are related to ‘miscommunications’ within those brain areas involved in auditory perception.

Older adults often have difficulty understanding speech when background noise is present. This is partly caused by timing problems in the brain, but those timing problems are difficult to measure in the clinic; frequently going undiagnosed and untreated. This research will investigate a new way of measuring timing problems by recording brain wave responses to speech sounds. This will be done in younger and older listeners and the results compared to how well each participant can hear speech sounds in noise. The results of the study will help us to understand the hearing problems that older adults often experience.

Through exploring inner ear hair cell regeneration as well as developing new therapies to treat presbycusis, age related hearing loss, this study will try and find a cure for hearing loss. This project is a continuation of the research in hearing restoration that has taken place at Sunnybrook for the last several years. It is hoped that eventually this research will unveil a pathway that will lead to regeneration of hair cells in the inner ear, resulting in a cure for this type of hearing loss.

This project is working towards determining if adults who have trouble hearing in noisy environments, can be retrained to listen successfully. This could lead to the development of an innovative auditory training program among individuals with hearing loss to improve their comprehension in challenging communication situations.

Lead Researcher: Dr. Liam BrunhamInstitution: University of British ColumbiaProject: Pharmacogenomics of Cisplatin – Induced Hearing Loss in Adults

Many patients who receive the life-saving chemotherapy drug cisplatin develop hearing loss as a consequence. Why some patients are affected by this drug and others are not, appears to be influenced by genetic differences. This study is exploring the genetic causes of cisplatin-induced hearing loss in adults, in order to minimize the risk for this adverse drug reaction, and prevent hearing loss in the future.

Lead Researcher: Dr. Karen GordonInstitution: The Hospital for Sick ChildrenProject: Cortical Activity in Long-term Cochlear Implant Users
This project focuses on the advantages and disadvantages of providing a cochlear implant in one ear to the auditory system of young children, as opposed to implants in both ears. This project is working towards understanding how much residual hearing is needed in the un-implanted ear to undo abnormalities and if bimodal hearing can be used to restore binaural hearing

Listening difficulties, especially hearing speech in noisy environments, is a common problem for children suffering from two hearing loss conditions, auditory neuropathy dys-synchrony (AN) and auditory processing disorders (APD). There are features common to both AN and APD and although little is known about the cause of these disorders, three different genes have been identified for hereditary AN. This study will investigate whether mutations in these genes affect the ear, auditory nerve and brain. It will also help determine if these mutations cause similar listening problems in children with AN or APD. Results from this study will help understand the similarities and differences between these two types of listening difficulties and will ultimately allow clinicians to help identify and treat children with these conditions.

Currently, in people, damage to delicate hair cells of the inner ear is irreparable, resulting in permanent, life-long hearing loss. Dr. Lin, along with other international researchers have discovered that birds, unlike people, have the capacity to regenerate inner ear hair cells, allowing for the complete restoration of hearing. Their work has led to the discovery of a particular protein that causes spontaneous hair cell regeneration in birds. It is believed that inner ear hair cell regeneration may be possible in people and they continue to investigate the proper combination of gene therapy and medication that could regenerate and restore hearing to the hundreds of thousands of Canadians with this type of hearing loss.

Researcher: Michael Sasha John, PhDInstitute: Rotman Research InstituteCo-researchers: Andrew Dimitrijevic, University of California Irvine; David Purcell, The University of Western Ontario, LondonProject: Neurophysiological Modulation Transfer Functions of Auditory Neuropathy Patients

People with Auditory Neuropathy (AN) have a healthy cochlea (the part of the ear that is responsible for converting sound waves into electrical impulses that allow our brain to understand sounds), but their brain does not process or synchronize the sounds correctly, which affects their ability to make sense of speech and language. This research will study the responses of the brains of these patients to changing rates of sound, compared to people with normal hearing. Results from this study will help audiologists to determine the best possible treatment for people suffering with this type of hearing loss.

The death of inner ear hair cells is a leading cause of hearing loss and inner ear dysfunction. Aging, noise and certain drug therapies (e.g. high doses of antibiotics, chemotherapy) can cause hair cell death. The production of free radicals in the ear has been shown to cause hair cell death in all of these cases. Currently many labs are evaluating the role of antioxidants for their ability to protect hair cells from the free radicals, but as yet, the mechanisms that trigger hair cell death are not well understood.

Having recently identified TRPM2, a protein that triggers cell death in other cells of the body and is also present at high levels in hair cells, this research will determine if this protein also triggers cell death in hair cells. If this is true, the researcher will then try to block this protein and reduce its effect on the inner ear hair cells. The impact of this study could be dramatic, potentially leading to new ways to prevent hair cell death, thereby preventing the loss of hearing and inner ear function.

Researchers:Aaron J. Newman, Manohar Bance, Dennis P. Phillips and Steven AikenInstitution: Dalhousie UniversityProject: Binaural Integration and Asymmetric Hearing Loss
We need a pair of ears to localize sound in space, understand speech and easily appreciate music. But what happens when a person has hearing loss in one ear? This common type of hearing loss can interfere with activities most of us take for granted, such as talking with someone in a busy restaurant. The goal of this research is to find out how different hearing ability between our two ears has to be before it fails to work normally. The outcome of this study will help clinicians determine the best treatments for those who suffer from hearing loss.

Researcher:David W. Purcell, PhDInstitution: The University of Western OntarioProject: Assessment of Infant Hearing Using Objective Audiometry and Bone Conduction

When hearing loss happens in an infant, it’s important to determine the cause so that the best treatment can be adopted. Although problems can occur in the inner ear or brain, the cause is sometimes a sound transmission problem in the middle ear. Since the vibration devices used to test for this possibility are calibrated for adults, they are not ideal for infants. This study will develop a way to objectively calibrate this diagnosis equipment for use with infants. Ultimately, it will improve our ability to differentiate between the various kinds of hearing loss.

Through previous research, we confirmed that when a specific gene (named xiap) is over-exposed, it delays the development of age-related hearing loss and provides protection against noise. We also established a method for transfection of this gene to the inner ear using viral carriers or vectors. However the vectors currently available cannot provide satisfactory transfection of this gene to the outer hair cells – the cell type in our inner ears that is most vulnerable to aging and other traumatic factors. This study will use special promoters to create new vectors and improve transfection by overcoming this shortfall. It will also provide the basis for gene therapy in the inner ear.

In half of children who are deaf at birth, the cause of the deafness is genetic. The most common genetic cause of deafness is two abnormal changes in the connexin 26 gene. It was previously identified that many deaf children have only one abnormal change in the connexin 26 gene instead of two. The research tested 50 deaf children with one abnormal change to see if these patients had a new second type of abnormal change not found by previous genetic tests. This study provided a better understanding of genetic deafness and in doing so, may lead to improved treatments for deafness.

In face-to-face communication, we understand better if we can see the speaker\’s lips moving. This study investigated the effects of lipreading on auditory evoked and oscillatory cortical activity with whole head magneto-encephalography (MEG). The intent of this is to develop and improve the methods for recording physiological correlates of speech understanding, leading to an objective tool for assessing functional changes during audiovisual training programs. This may also help the hearing impaired who experience problems following a conversation when they are in a noisy environment.

Current methods to obtain hearing thresholds in newborns and infants do not take into account the maturation of the young auditory system. These methods could lead to failure in identifying children with mild levels of hearing loss, who could be at risk for academic difficulties later in life. They could also lead to providing inappropriate amplification levels to infants with hearing impairments. The purpose of this study is to attempt to quantify this maturational effect during the first six months of life and provide corrections in order to reveal accurate hearing threshold values, at discrete periods of time during infancy.

Researcher: David W. Purcell, PhDInstitution: The University of Western Ontario, National Centre for Audiology, LondonProject:Contra-lateral suppression of distortion product otoacoustic emissions

The human ear produces quiet sounds, called otoacoustic emissions, that can be recorded in the ear canal with a sensitive microphone. This has been taken advantage of in a clinical test of the hearing of newborns. The current test is however, unable to tell whether there may be a problem in the brainstem above the inner ear. This study is designed to investigate the possibility of testing the neural connections between ears by providing noise to the opposite ear. If the response can be made to change reliably, then the measurement might be useful as a better clinical test.

Listening to a sound (e.g. a voice or music) requires an active process in which we can focus on a sound of interest and exclude other distracting signals. Thus, hearing involves not only sending sound information from the ears to the central brain (in what we call the ascending pathways), but also the central brain controlling or “gating” what gets through to the highest levels. These gating mechanisms are accomplished, in part, by descending auditory pathways in the brain. This project studies certain aspects of this important pathway and in particular, the mechanisms by which nerve cells in the system transmit signals.

Researcher:Steven G. Lomber, PhDInstitution: The University of Western Ontario, LondonProject: Maximizing the benefit of cochlear implant: Is earlier always better, or is there an optimal period?

Cochlear implants are new types of hearing aids that can benefit patients who have severe or profound hearing loss. This project concerns the areas of the brain which deal with auditory processing and looks into how such areas can adapt or develop processing ability when sound is presented through a cochlear implant device. This study is an exploration of the way in which the auditory areas of the cortex (the highest auditory areas in the brain) can represent or be activated by the electrical signals that are sent through a cochlear implant. The work will help us develop a new generation of cochlear implants, which may provide greater benefit than those presently used.

When we hear sounds (e.g. voices or music, street sounds) we do so together with other sensory inputs, in particular, vision. Being aware of an environment involves the integration of information from all the senses. As the brain ages, the ability to integrate these various stimuli can deteriorate. The ability of central auditory areas to identify and process sound information is reduced. One way of investigating the brain and its aging process is to use new brain imaging methods. This project will explore how the nerve cells in the brain change function with age. A further understanding of what happens to auditory processing in the aging brain will be useful in the prevention of hearing loss or in habilitation programs for the elderly.

Researcher: Susan D. Scollie, PhDInstitution: The University of Western Ontario, LondonProject: Sound localization and discrimination abilities of hearing impaired children

In addition to its ability to hear sounds and identify them, the auditory system can also determine where the sound originates from. Sound localization is very important. For example, when we are talking to somebody in a noisy room, the ability to localize the source of sound helps to make that particular voice clear. This aspect of hearing has been largely ignored in the assessment of hearing loss in subjects. In this project, the ability of children with various types of hearing loss to localize sound is being assessed. This work is very important in determining what deficits in sound localization might exist, and the information may be useful in providing habilitation for children with hearing loss. It may also aid in the design of new hearing aids that can provide better sound localization.

The brain pathways that transmit sound information from the ears to the central parts of the brain undergo an early developmental phase during which many things can interfere with or change normal development. One of the important transmission areas en-route is the midbrain region. In this study, the way in which nerve cells transmit information in the midbrain region is being investigated. The researchers wanted to determine whether there are particular changes to the way in which nerve cells communicate during early developmental periods. The work will demonstrate not only more about how the normal auditory brain system develops, but also what sort of deficiencies can arise because of hearing loss at an early age.

Newborn hearing screening programs indicate whether or not a hearing loss is present. To plan effective treatment, the amount of loss at particular frequencies and the amount of compensatory amplification required must be determined. The development of new techniques using the multiple auditory steady-state evoked response to measure temporal modulation transfer functions is proposed. This study also aims to establish age norms for optimum stimulus modulation rates and to improve the efficacy and accuracy of infant hearing tests.

Researchers: Navid Shahnaz, PhD; and Co-investigator: David Stapells, PhDInstitution: University of British Columbia, VancouverProject: Investigating the mechano-acoustical properties of normal and diseased middle ear in newborns

Otitis media is the most common childhood illness globally. If undiagnosed, it can affect general health, as well as speech and language development. Current infant screening protocols do not distinguish conductive from sensorineural loss. The study proposes to define the mechano-acoustic properties of middle-ear structures in normal and diseased newborns, and to develop diagnostic procedures. It also hopes to provide guidelines for developing effective and non-invasive procedures to detect middle ear infection in newborns, leading to improved treatment protocols.

Researcher: Jun Yan, MDInstitution: University of Calgary, Department of Physiology & BiophysicsProject: Neural mechanisms of learning-induced auditory plasticity: The role of cortical acetylcholine and corticofugal modulation

The ability of neural pathways in the cortex to re-form (examining the role of plasticity) is fundamental to auditory learning. The study examines the role of the cortical cholinergic system and corticofugal projections in auditory learning induced plasticity by mapping changes to the frequency tuning of cortical and midbrain neurons to electrical stimulation of forebrain paired with tonal stimuli. The intent is to increase understanding of the neural mechanisms of auditory learning.

Cerebral damage associated with stroke can result in central auditory processing disorders. The effect of stroke on behavioural test outcomes of auditory discrimination tasks requiring fine temporal processing (speech perception, recognition of complex sounds, ability to hear sounds in a noisy environment) is examined with the goal to increase understanding of central processing disorders that can disrupt speech perception.

Some middle ear diseases can “fix” the stapes, preventing sound transmission to the inner ear. Stapedotomy surgery bypasses the non-functional pathway with a piston prosthesis. This study researched piston parameters that affect acoustic energy transmission (in particular, diameter and mass). The goal of this study was to determine the optimal parameters with which to maximize energy transmission. It also included a comparison of the effectiveness of commercially available prostheses.

Researcher: Deitrich Schwartz, MDInstitution: University of British Columbia, VancouverProject: An EEG Test for Tinnitus

Patients with hearing loss often suffer from severe ringing in the ears (tinnitus), which may be worse than deafness itself. Doctors have no method for an objective assessment of tinnitus and are, therefore, unable to monitor, objectively, the success of an attempted therapy. In fact, there is no generally accepted therapy. The intent of this study is to develop an objective diagnostic test for tinnitus because we know that the brain produces electrical oscillations (brain waves) whenever a sound is perceived. The study will analyze the electrical brain waves produced by tinnitus itself and determine how they change electrical responses of the brain to normal sounds. The aim is to develop an electrical brain wave signature of tinnitus that can be used to measure this disturbing sensation, and to assess the effect that a treatment (e.g. a new drug), may have.

This research study investigates how the ear and brain hear sound. By playing sounds to a listener, the researchers can measure the ear\’s response to that sound using a small microphone placed in the ear canal. They can also record the brain\’s response to the same sound using sensors placed on the scalp. By combining these two types of measurements, they can calculate how long it takes the ear and brain to process sound. This will help us understand normal hearing, and improve our ability to recognize and treat hearing problems.

This research program will record the electrical brain activity that is generated when we listen to sounds. The goal is to relate a participant\’s perception of sounds with specific patterns of brain activity and to assess the effects of age on sound perception. These recordings will help us to understand how we perceive auditory events such as speech perception, and whether the brain is differently active in younger and older adults. Improvement in diagnosis, rehabilitation techniques, and hearing aids can be made by learning what cues are most important and salient for older adults when confronted with complex auditory scenes.

Researchers: Sylvie Hébert, PhD and Sonia Lupien, PhDInstitution: Université de MontréalProject: The role of Cortisol in Normal and Pathological Audition, with a Special Attention to Tinnitus

Cortisol is a hormone that is naturally secreted by the body in response to stress. Long-term effects of abnormally high levels of cortisol are damaging and associated with disease. Past research has demonstrated the involvement of cortisol in audition. This project aims to gain a better understanding of the role of cortisol in audition by integrating both normal and pathological aspects of audition (in particular, hearing loss and tinnitus) into a single, coherent framework.

The researchers\’ broad, long-term goal is to aid in the remediation of children who have central auditory processing problems that are linked to developmental language delay. Until recently, children with developmental language delay were thought to have an isolated disorder specifically of language processing. It has now become clear that many of these children also have some kind of impairment in the perception of sounds in which the timing of acoustic events is important. There is, however, much debate over the generality of this association and over the question of whether the auditory temporal processing problem is causally related to language delay. The challenge is that both auditory temporal processing and developmental language delay are umbrella terms, making it difficult to know whether the same kinds of children are being studied, or whether the same temporal processes are being explored, in current research. The purpose of this study is to resolve this issue by carefully studying performance on a broad range of auditory temporal processing tasks by a broad range of children with learning disabilities. This will enable us to determine which kinds of language-learning impairment have correlates in impaired auditory processing, and which kinds of auditory temporal processing operations are impaired.

A better understanding of the synaptic physiology and pharmacology of the central auditory system will lead to improved diagnosis and treatment of hearing disorders of central origin. During the last few decades, the great progress in dealing with peripheral hearing loss is due largely to advances in understanding the cochlea and its function. Similar advances in understanding the role of the central nervous system in processing auditory information will provide solutions to problems associated with sensorineural hearing disorders. The proposed research will contribute to this effort by providing a basic understanding of the physiological role of GABA receptors in the central auditory system. The outcome of the proposed research will be to improve our understanding of the neuronal mechanisms of auditory information processing, and suggest guidelines for diagnosis, treatment and rehabilitation of sensorineural hearing loss.

To use brain imaging techniques (MRI) in subjects with hearing loss and to follow the changes to the brain areas associated with hearing, while using hearing aids or during various habilitation therapies.

The ability to keep sequences of sound elements in proper order is essential for understanding and producing speech. This study will explore the degradation of these processes in children with hearing loss.

Researcher: Adrian James, MDInstitution: University of TorontoProject: Comparison of a novel hearing screening device Vivo 200 DPS and the Ontario screener; the correlation between pass-fail decision and audiogram.

A new method for testing hearing in babies which was developed at the University of Toronto will be compared to current “standard” methods in order to verify its utility for neonatal hearing screening.

In the context of health care economics, the quality of life and societal benefits of cochlear implantation in adults and the associated fiscal impacts on Canadian society will be considered.

Previously Funded Non-Medical Grants

The Hearing Foundation of Canada (THFC) historically supported a wide range of services for deaf and hard of hearing children and adults across Canada. Some of these past projects are outlined below. Since 2007, THFC has focused on medical grants exclusively and is not currently funding non-medical proposals.

Bringing Aid to Deaf Children and Adults in Developing Countries project –CIHS collected and provided refurbished hearing aids, audiological equipment, training programs and education to agencies and individuals in developing countries around the world. Through the humanitarian efforts of CIHS children with hearing loss have received their first hearing aids. Health providers also received training that enabled them to continually improve the health care of deaf and hard of hearing children and adults in their own country.

Auditory-Verbal Therapy project – Through successful national advocacy efforts of various organizations, such as The Hearing Foundation of Canada, the number of severely to profoundly deaf children in Canada who are now receiving a cochlear implant has increased dramatically. By bypassing the part of the auditory system that is damaged, this technological wonder translates sounds into signals that are sent to the auditory nerve, and are then recognized by the brain as sound. But receiving a cochlear implant is just the beginning. Auditory-Verbal Therapy enables a deaf child to interpret these new sounds in order to develop language and communication skills, so crucial to their success in the classroom and the community.

Shared Reading Program – Based on a project currently operating at the world renowned, Gallaudet University in Washington, D.C., this program allows hearing parents to read stories with their children who are deaf. Tutors, who are deaf, teach parents to sign a story from a written storybook using American Sign Language (ASL). A person proficient in ASL is videotaped as they sign the story. Families are provided with the tape and the book to practise at home. This was the first time many hearing parents were able to truly communicate with their profoundly deaf child.

Family Communication Program – How do hearing children share their joy, their thoughts, their fears with their deaf parents? The Family Communication Program, a special 12-week program brought a qualified sign language teacher into these families\’ homes and provided training to improve communication and ultimately, family relationships.

Silent Weekend project – By funding Silent Weekend, THFC provided a rare opportunity for deaf children and teenagers, along with their families, to come together for an educational and inspiring three days of learning.
Many of these families live in isolated communities along the B.C. coastline, making it difficult for deaf children and families to experience deaf culture and build relationships with other deaf children.

“Best in You” Project – Very little is offered in BC for psychosocial adjustment to hearing loss for hard of hearing youth. According to WIDHH, evidence from parents, teachers and youth is that they lack a personal and group identity as being “hard of hearing” – they have not developed the interpersonal and social skills needed to function in society and the workplace. The Best in You program assists young people to adjust to the impact of hearing loss in any communication situation.

Tactaid VII\’s for Profoundly Deaf Children project – Three specialized devices were purchased for deaf children whose hearing loss was so severe they were unable to benefit from regular hearing aids. The Tactaids belong to the agency and are loaned to the families until they are able to purchase their own unit or until the child receives a cochlear implant.

LSQ training and literacy for deaf youth and adults project –Literacy is an enormous obstacle for deaf youth, with the average 16-year old deaf student reading at the level of a hearing 8-year old. The funds were used to help the deaf youth and adults in their community increase their literacy skills and their ability to attain employment.